The macrocyclic ligands L2 and L3, containing a fluorescence emission properties, but interaction with the lone pairs of benzylic nitrogen atoms produces an efficient triethylenetetraamine and a tetraethylenepentaamine moiety linked to the methyl groups of 2,9-dimethyl-1,10-quenching of the emission. Such a quenching effect can be avoided by deactivation of the benzylic nitrogen atoms by phenanthroline, bind H + and Zn 2+ ions giving rise to modulation of the fluorescence emission intensity. The means of protonation or Zn 2+ complexation. Hence, L2 and L3 behave as chemosensor for H + and Zn 2+ , the equilibrium constants and the enthalpy changes for ligand protonation were determined by means of pH-metric and photochemical properties of the ligands being modulated by the formation of different protonated and complexed species. microcalorimetric methods in 0.1 M Me 4 NCl solutions at 298.1±0.1 K. Also the stability constants of the Zn 2+
In the case of L3, the fluorescence emission is also controlled by the metal to ligand molar ratio, because of the formation complexes were determined under the same experimental conditions. L2 forms only mononuclear complexes, while L3 of an emissive binuclear complex. also forms dizinc(II) species. The phenanthroline group has escence emission properties of phenanthroline with the high
Results and Discussion